Process for preparing a composition containing pentacalcium orthoperiodate

ABSTRACT

THE PREPARATION AND USE OF PENTACALCIUM ORTHOPERIODATE, CA5(IO6)2, IN A SALT BLOCK AND FEEDS AS AN ASSIMILABLE SOURCE OF IODINE FOR THE SUPPLEMENTATION OF THE DIET OF ANIMALS.

Aprll 30, 197.4 5, ANDELFlNGER E-TI'AL 3,8Q8,310

PROCESS FOR PREPARING A COMPOSITION CONTAINING PENTACALCIUM ORTHOPERIODATE Original Filed Aug. 28, 1967 CORRELATION BETWEEN QUICK LEACH AND LEACHING RATIO o E :1: 2 LL] l-oO=....--. l I

O 1 2 1 O I I I I O 5 l0 I5 20 25 QUICK LEACH 3,808,310 Patented Apr. 30, 19 7 l United States.

Int. C]. (101]) 11/00 US. Cl. 423-472 Claims ABSTRACT OF THE DISCLOSURE The preparation and use of pentacalcium orthoperiodate, Ca (IO' in a salt block and feeds as an assimilable source of iodine for the supplementation of the diet of animals. Y

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional of our application, Ser. No. 881,570, filed Dec. 2, 1969 now US. Pat. No. 3,749,579, which, in turn, is a divisional of ourfapplication, Ser. No. 663,784, filed Aug. 28, 1967 now US. Pat. No. 3,526,508. t

BACKGROUND OF THE INVENTION 1) Field of the invention The field of this invention is broadly that of iodine supplementation of the diet of animals, and the compositions and means for providing such supplementation.

Mineral elements in general and specifically iodine have been well established as essential elements in the-nutrition of both man and animals.

The following, from the publication Nutrient Requirements of Dairy Cattle, National Academy of Sciences National Research Council, third revised edition, p. 8 (1966), publication 1349, is indicative of the need in general for mineral elements in the diet of dairy cattle:

The mineral elements required by dairy cattle are: Calcium, phosphorous, magnesium, potassium, sodium, chloride, sulfur, iodine, iron, copper, cobalt, manganese, zinc, and selenium. These mineral elements are needed for bone formation, as constituents of the proteins and lipids that make up the muscles, organs, blood cells, and other soft tissues, and in many enzyme systems of the body. They are concerned in the maintenance of osmotic relationships and acid-base equilibria, and exert characteristic effect on the irritability of muscles and nerves.

Page 10 of this same reference sets forth the necessity of iodine in the diet of cattle:

The lack of iodine is recognized as the-principal cause of goiter in newborn calves. The goiter areas are'foun'd primarily around the Great Lakes and Westwardto the Pacific coast. In these regions, iodine supplements have been shown to be necessary. The use of iodized salt containing 0.015 percent iodine incorporated at a 1 percent level of the grain ration has proved elfective. When iodized salt is stabilized to retard loss of iodine, a productcontaining 0.0076 percent iodine (0.01 percent potassium iodide) will probably provide the-needed iodine supplementation. The use of stabilized iodine is recommended as a supplement to the ration of pregnant'cows'on farms where goiter has been known to occur among newborn calves.

Other publications of the National Academy of Sciences National Research Council, relating to Nutrient Requirements of Domestic Animals detail the essentiality of iodine in the diets of swine, sheep, and laboratory animals.

t (2) Description of the prior art- It is conventional in the dairy and livestock industries to supplement animal diets with trace minerals 'proven essential for good nutrition.,0ne method of conveniently accomplishing this is by inc orporating the necessary trace minerals into an animal feed or in loose salt. Another method of conveniently accomplishing this is by incorporating the necessary trace minerals into blocks of salt which are randomly placed in the pasture for the animal to lick according to its natural desire for salt, This type of dietary supplementation is known as ad libitum or free choice feeding and is believed by nutritioniststo be a good means for providing those elements which are apt to be lacking in the ordinary diet. v

A salt block is generally formed by high pressure compression ofsalt into a self-supporting form, usually'rectangular in cross-section and weighing about 50 pounds. When placed in the pasture, the block is exposed to weathering and leaching by water. It is therefore important that none of the trace minerals is preferentially leached from the block by rain or snow leaving the block deficient with respect to a specific mineral.

Substancescurrently being used as a source for iodine in a salt block are potassium iodide, thymol iodide, calcium iodate, ethylenediamine dihydroiodide and diiodosalicylic acid, Potassium iodide, calcium .iodate and ethylenediamine dihydroiodide are good nutritional sources of iodine but have the disadvantage of being preferentially leached from a salt block by rain or snow, leaving the surfaceof the block deficient or even entirely void of iodine. Diiodosalicylic acid has excellent leach resistance, but its nutritional availability or assimilability has been questioned. Thymol iodide is relatively expensive.

Accordingly, it would be desirable to overcome these disadvantages of the presently used iodine sources in order to provide more eifective dietary supplementation.

It is therefore an object of the present invention toprovide a novel, nontoxic, nutritionally available and easily assimilable iodine source for animal feeding;

- It isanother object of the present invention to provide a method for iodine supplementation of ananimal diet by free choice feeding from a salt block containing an iodine source which is not preferentially leached by water from said salt block.

It is another object of the present inventionto provide a novel, nutritionally available iodine source for incorporation in a salt block, which iodine source isresistant to preferential aqueous leaching therefrom. I

It is a further object of the present invention to provide a simple, efiicient and relatively inexpensive process for preparing said iodine source. I v

It is a still further object of the present invention to provide salt block compositions containing an assimilable, nutritionally available iodine source which is resistant to preferential aqueous leaching therefrom.

. It is another object of the present invention to provide a method for preparing salt block compositions containing an assimilable iodine source for animal diet supplementation, which iodine source is not leached from said SUMMARY OF THE INVENTION The foregoing objects of thisinvention are accomplished by the preparation of pentacalcium orthoperiodate, Ca (IO ,'to the novel use of such compound as a nutritionally available and easily assimilable source of iodine supplementation of animal diets, particularly when incorporated into salt blocks, to salt block compositions containing pentacalcium orthoperiodate as the principal iodine-bearing constituent, and to the preparation of such salt block compositions.

Broadly, according to the present invention, pentacalcium orthoperiodate is prepared by admixing calcium iodate with a basic compound selected from the group consisting of calcium hydroxide and calcium oxide in the concentration of from about 0.08 to about 0.5 mole of calcium iodate per mole of basic compound until thoroughly blended, heating the admixture to a temperature of from about 425 C. to about 550 C. to produce pentacalcium orthoperiodate, and cooling the resulting reaction product. The crude cooled reaction product may be washed with dilute acid until the pH of the washings is reduced to about 7, and thereafter the resulting insoluble residue dried. This acid washing step, using sulfuric acid or the like, produces a pentacalcium orthoperiodate product having a purity in excess of 90% or at least 90% purity.

The use of calcium iodate in a concentration in excess of about 0.5 mole per mole of basic compound results in excessive iodine volatilization during heating, a condition which not only is wasteful of iodine, but also presents problems with respect to equipment corrosion and iodine disposal of recovery. The use of less than about 0.08 mole of calcium iodate per mole of basic compound results in a final product which has substantial and undesirable proportions of unreacted basic compound. Calcium oxide or calcium hydroxide may be used interchangeably in the process, or a combination of the two may be employed, if desired. However, it has been found convenient to employ calcium hydroxide for routine production of the product.

A heating temperature substantially lower than about 425 C. results in a product which is characterized by an excessive calcium iodate content. An excessive calcium iodate concentration adversely affects the leach-resistant properties of the product when incorporated into a salt block. The optimum time of heating is approximately one hour, although, as is readily understood, heating for pcriods of time more or less than one hour does not materially affect the process or product.

More particularly, the preferred process for the preparation of pentacalcium orthoperiodates comprises thoroughly admixing calcium iodate with calcium hydroxide in the ratio of about 0.15 mole of calcium iodate per mole of calcium hydroxide, heating the admixture at a temperature of about 500 C. for a period of about one hour, cooling the mass and washing with dilute sulfuric acid until the washings have a pH of about 7, and thereafter drying the insoluble residue. As hereinbefore stated, this process yields substantially pure pentacalcium orthoperiodate.

Another of the foregoing objects of this invention is accomplished by the administration to animals of pentacalcium orthoperiodate as an iodine supplement. Administration is most easily accomplished in the case of livestock feeding by admixing said pentacalcium orthoperiodate with sodium chloride and compressing the admixture into a self-supporting form, usually a rectangular block. The so formed block is then placed where the animals graze so that they can partake thereof to satisfy their natural salt hunger and at the same time ingest iodine essential for good nutrition. The concentration of pentacalcium orthoperiodate used in a salt block is about 0.03 weight percent, which provides about 0.01 weight percent of iodine. It is understood that this concentration may be increased or decreased as desired to achieve special nutritional effects.

For the purpose of incorporating pentacalcium orthoperiodate into loose salt, a salt block, or other animal feeds, it is convenient to incorporate directly into the feed the product obtained by omitting the step in the preparation of pentacalcium orthoperiodate which involves extraction with dilute acid to provide essentially pure pentacalcium orthoperiodate. It has been found that the product obtained by cooling the heated admixture of calcium iodate and calcium hydroxide, without acid extraction thereof, is essentially a basic pentacalcium orthoperiodate composition composed principally of pentacalcium orthoperiodate as the major iodine-bearing compound in a matrix comprising minor proportions of calcium hydroxide, calcium carbonate, calcium oxide and calcium iodate. These matrix substances in admixture with pentacalcium orthoperiodate do not affect its performance as an assimilable iodine source which, when incorporated into a salt block, is resistant to preferential aqueous leaching therefrom. Further, these matrix substances are expressly permissible as components of an animal feed according to the applicable regulations of the Food and Drug Administration.

For these reasons, testing of pentacalcium orthoperiodate with respect to toxicity, assimilability and nutritional availability, rat feeding tests, and evaluations of resistance to aqueous leaching from a salt block has been conducted on basic pentacalcium orthoperiodate compositions. These tests, hereinafter more fully described, have demonstrated that pentacalcium orthoperiodate is both nontoxic and effective as a dietary supplement in preventing iodine deficiency. Pentacalcium orthoperiodate is quite insoluble in an aqueous alkaline or neutral medium. It is, however, soluble in an acidic medium. Investigation has shown that in an acidic medium such as abomasum juice, the gastric juice found in the fourth stomach of a bovine animal (pH 3.0), pentacalcium orthoperiodate is reduced to iodate and iodide, each of which is well established as a source of nutritionally available, easily assimilable iodine, and each of which is permissible as a trace mineral additive to animal feeds according to applicable regulations of the Food and Drug Administration.

This reduction to iodate and iodide is understandable in view of the fact that abomasum juice contains a variety of organic reducing substances and enzymes derived from pasture grasses, silage, grain, dry feed and molasses, e.g., cellibiose, starch, sugar (sucrose and arabinose), glycogen, arabitol, trypsin, pepsin, cysteine cystine histidine protose (partially hydrolyzed protein), chlorophyll, nucleic acid, and Lactobacillus acidiphilus.

Repeated laboratory tests have also established that each of the above substances in an acid medium is effective to reduce pentacalcium orthoperiodate to iodate and iodide in accordance with the following equation:

Soluble in One disadvantage common to many of the currently used iodine sources is that, when incorporated into a salt block and exposed to the weathering action of rain and snow, they are preferentially leached or dissolved, leaving the surface of the block deficient or even entirely void of iodine. It was unexpectedly found that pentacalcium orthoperiodate, when incorporated into a salt block, is not preferentially leached therefrom by water. Under conditions of actual outdoor exposure to weathering for a period of twenty-eight days, it was found that the surface iodine content of a salt block containing pentacalcium orthoperiodate was essentially the same at the end of this time as it was when the block was originally formed. In addition to field trials under conditions of actual exposure to rain, laboratory tests, hereinafter more fully described, further establish that pentacalcium orthoperiodate is resistant to preferential dissolution for a salt block by water and that the concentration of iodine in a salt block remains essentially constant under the most severe conditions of high humidity.

1 Amino acids.

For a more complete understanding of the present invention, reference is now made to the following specific examples illustrating the preparation of essentially pure pentacalcium orthoperiodate, the preparation of compositions containing pentacalcium orthoperiodate as the prine i EXAMPLE6 :Mole ratio of calcium iodate to calcium hydroxide ,1 The procedure of Example 2was repeated except that cipal iodine-bearing constituent, the evaluation of such 5 the te p r W and 69-55 grams of calcium compositions with respect to toxicity, nutritional availiodate Were admixed 303581111115 olf'calcium yability andassimilability, ,and resistance to aqueous leachdl'oxide t0 PFQVide a mole, ratio 0f l m iodate to l ing when incorporated into a salt block, and to the prepcium hYdI'OXide 0f aration of salt blocks containing said compositions. E J

EXAMPLE 1' The procedure of-Example 2 was repeated except that Preparation of essentially pure pentacalcium thetemperature was 525 and 75.37 grams of calcium orthoperiodate 1 V penodate were admixed with 24.63 grams of calcium hy- 5 drox1de to providea mole ratiozof',calciumiodate to cal- Calcium "iodate and calcium hydroxide were dr'ycium hydroxide of 0.6121; 1 1 blended in the mole ratio oi 0.15 mole of calcium iodate EXAMPLE. 8 g I per mole of calcmm hydroxlde until a homogeneous mixr v ture was obtained. The mass was then heated for one hour 7 One hundred grams of calciumjodatealone were heated at a temperature from about 495- C. to about 520 C., at a temperature of 57.5? C.-for'a period,of about one after which time it was allowed to cool. The cooled admixhour. I ture was washed with dilute sulfuric acid until the wash- EXAMPL ings reached of about The {esidue was i dried One" hundred-grams of calcium iodate alone were to constant Welght q Pw m orthopenodate of heated at a temperature of 660 C. for aperiod of one about 93 Percent purity. I 1

' Each of the products obtained in foregoing examples A EXAMPLE 2 to 9 inclusivej was analyzed foritotal iodine content, and Preparation of compositions containing pentacalcium orfor the ions orthoperiodate, iodate, and iodide, each of thoperiodate as the principal iodine-bearing constituent which ions was calculated to the corresponding calcium (mole ratio of calcium iodate to calcium hydroxide of compounds I Y 0.15:1) 'Iheresults are set forth in Table 1.

TABLEI Percent- Mole Pentap I ratio 'Iempercalcium Weight Total initial Ca(IOt)i: ature, ortho- Calcium Calcium Total loss on iodine (as Example Ca(OH)z C. periodate iodate iodide iodine heating I2) lost 495 00.7 as" 0.25" t 29.8 -5;-9 0 520 64.2. 7.9. 0.15 30.4 .,10.4. 2.1 495 41. 1 4. 4 0. 7 19. e s. 7 Nil 455 -s1.'o 6.7 0.44 50.7 15.4- 20. 4 465 73.0 17.0 0. 29 40.3 24.8 32. 1 525 72.0 19.0 1.1 I 41.9' 31.3 40.8 575 r 9.0 88.9. 0 61.4 20.7 24.4 V 660 68.6 22.9 1.5 43.1 63.9 75.9

1 No calcium hydroxide. 7 Calcium iodate (43.34 grams) and calcium hydroxide The results of-Examples 2 to 7 inclusive demonstrate (56.66'grams), a mole ratio of 0.15 mole of calcium thata'mole ratio'of calcium iodate to calcium hydroxide iodate per mole of calcium hydroxide, were dry-blended from about 0.08:1"to about 0.6:1 is operable to provide until a'homogeneous mixture was obtained. The mass was the pentacalcium orthoperiodate compositionsofthe presheated for one hour at 495 C., after which time the adent invention, althoughthe preferred mole ratio or calcium mixture was cooled to provide a composition containing iodate to calcium hydroxide is about 0.15:1. pentacalcium orthoperiodate as the principal iodine-bear- Examples 8 and 9 are illustrative of the 'well known ing compound with minor amounts of calcium oxide, calprocess for preparing'p'entacalcium orthoperiodate by the cium carbonate, calcium hydroxide and calcium iodate. thermal decomposition of calcium iodate alone. Th

EXAMPLE 3 v equation for such reaction is asfollows. v The procedure of Example 2 was repeated except that 5 8004): 0850 6)! 4 4 904 the temperature was 520 C. A e 7 LE 4 As as seen from the equation, the theoretical max1mum EXAMP yield of pentacalcium orthoperiodate, based on calcium Mole ratio of calcium iodate to calcium hydroxide iodate, is only 33 percent by weight. Or to stateit difof 0.08:1 ferently, there is a loss of percent of product in this The procedure of Example 2 was repeated except that i to t m l 9 wilatile Pq P and oxy- 27.67 grams of calcium iodate were admixed with 72.33 i l? 1055 i loan-{e ptohlbltlye from an grams of calcium hydroxide to provide a mole ratio of econgmlq standpomt' and preclude? calcium iodate to calcium hydroxide of 0.08 to 1. merclal use of thermardecompogmon of calclilm lodatefor the preparation of pentacalcium orthopenodate. EXAMPLE 5 Thus, in Example 8 where the temperature of reaction is controlled at about 575 F there is only a 9 percent Mole ratlo of calclum lodate to calclum hydroxlde conversion to pentacalcium orthoperiodate. Where the of 03:1 thermal decomposition of calcium iodate is conducted at The procedure of Example 2 was repeated except that a h gh r p i as in p 9, although W.- the temperature was 455 C. and 60.47--grams of calsion to pentacalcium orthoperiodate is accomplished, cium iodate were admixed with 39,53 grams of calcium there is a concomitant iodine loss of 75.9 percent, which hydroxide to provide a mole ratio of calcium iodate to loss is totally unacceptable .from an economic POi t' f calcium hydroxide of 0.311. View.

7 RESISTANCE TO PREFERENTIAL LEACHING BY WATER When an iodized salt block is exposed to rainfall or high humidity, it loses salt in the form of brine. This brine contains iodine in proportion to the solubility of the iodine source used. Ideally, the brine should contain an iodine to salt ratio equal to that in the initial block. This would result in the block itself maintaining its initial iodine to salt ratio throughout its entire life.

Since the leaching ratio is defined as:

Iodine/ salt ratio in the leachings Iodine/salt ratio in the original salt block the ideal situation would give a leaching ratio of 1.0. If the iodine is being preferentially leached from the block, the leaching ratio will exceed 1.0, and the numerical value will be a relative indication of the degree of preferential leaching. If the leaching ratio is less than 1.0, a rather insoluble iodine source is indicated, meaning that iodine content of the remaining block is being maintained or perhaps even slightly increased. To make a comparison of leaching ratios, a standard test called the leaching ratio test was developed, in which salt pellets containing various iodine sources were subjected to leaching in order to determine their iodine leaching characteristics. A complete description of the leaching ratio test method follows.

LEACHING RATIO METHOD (A) Preparation of test pellets Inch Diameter 1 Thickness 0.33

The pellet size and shape can be approximated by stacking five twenty-five cent coins.

A basic pentacalcium orthoperiodate composition prepared according to Example 2, containing about 64% by weight of pentacalcium orthoperiodate, was tested for leaching properties, by admixing 0.0345 gram of this product with 100 grams of salt to provide an iodized mixture containing about 0.01 percent by weight of iodine. This mixture was pelletized as previously described.

The pellet was weighed on an analytical balance, then exposed in a desiccator at 100% relative humidity for a period of four days. During this time the test pellet absorbed moisture, forming a brine which dripped into a beaker.

The brine was collected, measured, and analyzed for both salt and iodine content; from these values, the leaching ratio was calculated. As a check on the accuracy of the iodine analysis, the leached pellet remaining was also analyzed for iodine content; total iodine found in the leached pellet plus the leachings was compared with the known initial iodine content.

RESULTS A leaching ratio of approximately 1.0 was obtained indicating that the basic calcium orthoperiodate composition is not subject to preferential leaching from a salt block.

QUICK LEACH METHOD Grams iodine in solutionX Grams iodine in original 0.1 gram sample =Percent quick leach Analysis of six different samples by the leaching ratio and quick leach methods respectively gave the following results:

Leaching Quick ratio leach The graph obtained by plotting the values obtained for l aching ratio along the ordinate versus the values obtained for quick leach along the abscissa is indicated in the attached drawing.

The attached graph shows the correlation of leaching ratio and quick leach. A quick leach value of 7.0, indicating that 7% of the total iodine in the sample is leachable, corresponds to a leaching ratio of 1.0. Quick leach values less than 1.0 indicate the desired degree of insolubility in the leaching medium, whereas values greater than 1.0 indicate proportionately greater dissolution than desired.

The composition of Examples 2 to 9 inclusive were tested for resistance to aqueous leaching when incorporated into a salt block by the aforedescribed quick leach method. The results obtained were as follows:

Composition: Quick leac Example 2 6.8 Example 3 8.4 Example 4 2.9 Example 5 3.9 Example 6 3.9 Example 7 3.3 Example 8 89.0 Example 9 6.4

It is seen from the graph that the quick leach values of Examples 2 to 7 inclusive correspond to leaching ratio values of from about 1 to about 0.5, which values attest to the leach resistant characteristics of the foregoing compositions when incorporated into salt blocks. The unacceptable quick leach of 89.0 for Example 8 correlates with a pentacalcium orthoperiodate content of only 9.0%. Although the quick leach value of 6.4 for the composition of Example 9 is satisfactory, the 75.9% loss of iodine in the preparation of pentacalcium orthoperiodate by thermal decomposition of calcium iodate precludes the commercial use of this process.

TOXICITY The oral toxicity of a basic pentacalcium orthoperiodate composition containing about 60% pentacalcium orthoperiodate and a total iodine content of 29.03% as aqueous suspension to groups of five fasted male albino rats of the Sprague-Dawley strain weighing -146 grams. The oral administration was performed by the I was determined, together with calcium iodate as a control, in the following manner:

Each of the products was administered as a 25% use of a syringe with a modified 17 gauge hypodermic needle as an oral feeding tube. The animals were observed following dosing and over a subsequent fourteen-day observation period. At the conclusion they were weighed and sacrificed.

Calculation of the LD and 95% confidence limits was performed by the method of moving averages, using the tables constructed by Weil (Weil, C. 8.: Tables for Convenient Calculation of Median Effective Dose (LD and ED and Instruction in Their Use, Biometrics, 8, 249 (1952).

From the number and distribution of deaths that occurred the acute rat oral LD of the pentacalcium orthoperiodate composition was found to be 7.07 (no range calculable) gm./kg. and the acute rat oral LD of the calcium iodate control was calculated to be 3.53 gm./kg. Based upon the iodine content of the samples, the LD for basic pentacalcium orthoperiodate is 2.05 gm./kg. and for the calcium iodate 2.28 gm./kg., demonstrating that the toxicity of pentacalcium orthoperiodate is comparable to that of calcium iodate.

NUTRITIONAL AVAILABILITY OR ASSIMILABILITY Wheat gluten 18 Brewers yeast, U.S.P. 2 Calcium carbonate 1 Sodium chloride 1 Portions of this diet were fortified separately with two well known iodine sources, potassium iodine and calcium iodate, and with a basic pentacalcium orthoperiodate composition respectively. To insure a uniform mixture, the pulverized iodine compounds (16 to 44 mg.) were premixed with a small amount (100 g.) of the test diet. The premix was then thoroughly blended with increasing amounts of diet until the desired concentration was obtained. Enough of each mix was prepared to last the eight weeks of the test.

The amount of iodine added to the diets was chosen at 150 micrograms per kilogram of food since it has been determined that difierences between compounds show up best at this level.

Analysis of the diets for iodine gave the following results:

MICRO GRAMS OF IODINE PER KILOGRAM OF FEED Low iodine diet as received:

Sample 1 42. 5 Sample 2- 42. 5

Average 42. 5

Diet with 150 microgJkg. of In (as potassinm iodide added:

Sample 1 194 Sample 2 191 Average 192. 5 42. 5 =150.

Diet with 150 microg./kg. oi I: (as

Ca(IOs)a added):

Sample 1. 197 Sample 2. 188

Average 192.5 42. =150.00

Diet with 150 microg./kg. of I: as pentacalcium orthoperiodate (Ca5(IOa)2 added:

Sample 1. 188 Sample 2. 194

Average 191 42. 5 =148. 5

Weanling (21 days) Sprague-Dawley female albino rats were individually weighted and randomly distributed two per cage in twenty cages. Free choice of feed was allowed from a cup with a top and a hole in the middle to minimize spillage. Feed consumption was determined by recording the amount added to each cage. Spillage was determined by collecting it in a pan to the center of which the feed cup was fastened and in a tray under the cage. No significant amount of spillage was observed in any of the cages. Water was available at all times from water bottles on the sides of the cages.

Weight gains were determined by weighing the rats individually at the start and at the end of the experiment. One rat in each cage was marked with black ink on the top of its head for identification.

The duration of the experiment was eight weeks.

At the end of eight weeks the animals were sacrificed and the thyroid glands were carefull removed and weighed. The results are tabulated in Table 2.

TABLE 2.RESULTS OF RAT FEEDING TEST Basic pentacalcium ortho- Potasperiodate sium Calcium composi- Control iodide iodate tion Iodine added to feed, micrograms per kilogram None 150 150 150 Total iodine by analysis,

micrograms per kilogram- 42. 5 192. 5 192. 5 191. 0 Number of rats 10 10 10 10 Average feed consumption for 8 weeks, grams per rat 577 610 618 618 Average final body weight,

grams 144 152 152 154 Average initial body Weight, grams 43 44 44 45 Average weight gain, grams. 101 108 108 109 Average weight of thyroid,

milligrams 30. 8 14. 9 17. 0 16. 2 Averlaige weight oiotdlyrold, mi rams per grams body weight 21. 4 9.8 11. 3 10- 5 The average weight gain together with the decreased weight of the thyroid gland attest to the fact that pentacalcium orthoperiodate is as assimilable and effective as potassium iodide of calcium iodate in preventing iodine deficiency.

While several embodiments of this invention are suggested above, it will be understood of course that the invention is not to be limited thereto, since many modifications may be made and it is contemplated therefore by the appended claims to cover any such modifications as fall within the true spirit and scope of this invention.

We claim:

1. A process for preparing a composition containing pentacalcium orthoperiodate comprising admixing calcium iodate with a basic compound selected from the group consisting of calcium oxide and calcium hydroxide in the concentration of from about 0.08 to about 0.5 mole of calcium iodate per mole of basic compound, heating the admixture at a temperature from about 425 C. to about 550 C. to produce a pentacalcium orthoperiodate, and cooling the resulting reaction product.

2. A process according to claim 1 wherein the cooled reaction product is washed with dilute acid until the washings have a pH of about 7, and thereafter drying the insoluble residue to produce a pentacalcium orthoperiodate of at least purity.

3. The process of claim 1 wherein the mole ratio of calcium iodate to basic compound is about 0.15:1 and the temperature of heating is from about 495 C. to about 520 C.

References Cited J. W. Mellors book, A Comprehensive Treatise on Inorganic and Theoretical Chemistry, vol. 2, 1922 ed., p. 413, Longmans, Green & Co., New York, publishers.

EDWARD STERN, Primary Examiner US. Cl. X.R.

UNITED STATES PATENT oF-FIcE CERTIFICATE OF CORRECTION Patent No. 0 Dated April 30, 1974 Inventor(s) George F. Andelfinger and Eugene J. 'Kuhajek It isvcertified that error' appears in the above-identified patent and that said Letters Patent are hereby corrected as shown 'belowz Col. -3, 1. 26 "of" should be or Col. 6 l. 13

"periodate" should be iodate Col. 6, 1. 55 The" formula:

should read:

$Ca(IO 2 Andelfinger, et al. p I U. S. Patent No. 3,808,310 Patented April 3O, 1974 Page Two "to I .7 V Col. 9,- 1. 4 "Und r the heading m my" l delete the first two paragraphs and insert'uthe following? i The oral toxicity of a basic pentacalcium orthoperiodate composition containing about 60% pentacalcium'orthoperiodate anda total iodine content of 29.03% as I was determined, together with calcium iodate as a control, in the following manner-:2

Each of the products was administered as a 25% aqueous suspension to groups of five fasted male albino rats of the sprague-Dawley strain weighing 105 l46*grams. The oral. administration was performed by the use of a syringewitha modified 17 gauge hypodermic needle as an oral feeding tube. Theanimals were, observed following dosing and over a subsequent fourteen-day observation period. At the conclusion they were weighed and sacrificed. I 7

Andelfinger, et a1. U. S. Patent No. 3,808,310 Patented April 30, 1974 Page Three Col. 9, l. 40 After "potassium", delete "iodine" and insert iodide Col. 9, l. 50 "food" should be feed v Col. 9, l. 60 After "iodide" insert a parentheseis Col. 9, l. 70 v After the formula insert a parenthesis Col. 10, l 42 "of" should be or Signed and sealed this 1st day of October 1974.

(SEAL) Attest McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents 

